Technique for Repairing Stucco Exterior Walls

Before patching the stucco, repair the leak that caused the damage.

The beauty and color of California homes is attributed to O.A. Malone, a plaster manufacturer who was the first to market colored, pre-packaged stucco in 1927. Many of the homes using the products are still in existence today and still have the original stucco. Stucco is most often damaged as the result of water from leaking roofs or pipes that causes the wall to be over saturated for extended periods of time. These damaged areas are easily repaired and there are several household items that will help you mimic the look and texture of the existing stucco and keep its historic beauty intact.

1

Chip away the edges of the loose or damaged stucco with a mason’s chisel and hammer. Continue chipping the areas all the way down to the wire mesh. Clean the area with a wire-bristle brush to remove any loose dust and debris. Wipe the entire area with a damp rag to pick up any remaining dust.

2

Cut a new piece of wire mesh if the old mesh is damaged or rusty. Nail the new piece of mesh into the repair area, using galvanized roofing nails. Spray the patch area with water from the spray bottle.

3

Mix a small amount of the stucco mixture according to the manufacturer’s instructions. Do not mix more than you can use in 20 minutes as it will begin dry out and won’t adhere to the wall properly.

4

Color-match older stucco by having a professional mix the stucco for you. Alternatively, take a chip of the old stucco to your local paint supply store and ask a sales representative to match the color and tint a gallon of paint for you. For newer homes, check to see if the color mix for your stucco is still being sold at your local building supply store.

5

Spread a 1/4-inch layer of the mixture into the hole, using a brick trowel. Do not get the mixture on the existing stucco and immediately wipe away any drips. Scrape the patched area with the edge of the trowel in a cross-hatched pattern. Keep the mixture moist while it cures for 24 hours.

6

Mix another small batch of the stucco and apply a second 1/4-inch coat in the same manner. Allow it to cure another 24 hours. Keep the patched area moist during the curing process. In some instances, two coats are enough to fully repair the wall. If not, mix and apply a third coat.

7

Match the finish on the new patch to the finished texture on the existing stucco while the final coat is still wet. Use the trowel to create a smooth surface or blot a damp sponge against the wet mixture to mimic stippling. Use a wadded piece of cloth to achieve a random and gentler stipple pattern. Alternatively, use a broom for matching swept or stippled patterns.

Things You Will Need

Mason's chisel

Hammer

Wire mesh

Misting spray bottle

Water

Prepackaged stucco mixture

Brick trowel

Sponge

Cloth

Broom

Tip

Always use a fresh batch of stucco for each layer you apply. Even if kept in a sealed container, the mixture will not be as stable if it is not fresh and can cause the patch to chip or break away prematurely.

Wait seven days for the patch to fully cure before painting. Use only acrylic latex paints that are designated for stucco.

Warning

You must have a good working knowledge of cement mixes and coloring them if you choose to mix your own stucco as it is extremely easy to destroy the mixture before you get finished adding the ingredients.